Can すみません always be used in place of ありがとう? What's the difference?
When using すみません to express thanks, what other words are used with it?
Could you show me some examples?
すみません is used to express thanks when you want so express gratitude for someone going out of their way for you, or you that you feel like you inconvenienced them by receiving their effort. Another part is someone doing something unexpectedly for you. Of course ありがとうございます also fits in the same situations, too.
Simple clear examples would be someone pouring you a glass of drink at a party; someone in the office bringing you a document you asked about the other day. I learned this use of すみません in these kinds of situations.
To say that you can always use すみません instead of ありがとう would be incorrect I feel. For example, during my language learning time I have received ongoing instruction from an older friend. He explained when saying expressing deep appreciation, I should unhurriedly say ありがとうございました with a bow. In these situations, すみません would be too short and wouldn't carry the same feeling.
Also, to make it even more interesting, it is fine to say "すみません。ありがとうございます。" in the same sentence but I don't believe there are many other words one would usually use with すみません though.
すみません carries more a feeling of "you have done something for me, and I am in debt" than ありがとう, which is more like "you have done something for me, and so I thank you".
I would say it is always safe to use ありがとう, but perhaps not すみません as it can be a little weaker in gratitude. Also elongating ありがとう->ありがとうございます/ありがとうございました carries more of a deeper feeling to it.
For example, imagine while out and about someone holds a door open for you. A quick little bow and a すみません or ありがとう is appropriate. However, if someone just had to do a lot of work for you, and they are on your social level or higher, you must thank profusely. Simply saying すみません or ありがとう is fairly offensive, as it does not show the proper level of gratitude you should be showing. Only ありがとうございます/ありがとうございました is appropriate here.
Furthermore, when detailing what you are thanking the person for, ありがとう forms a better sentence with something like: くれてありがとう. くれて,すみません doesn't really work as well.
Here is one example. You are taking the elevator to the 8th floor. Usually there will be one person holding the "open the doors" button. In this particular case, you will most often hear people say すみません to express gratitude. Using ありがとうございます in this case is kind of uncommon, though is not wrong to say it.
On the other hand, if you buy something on a store, the clerk will no doubt say to you ありがとうございます/ありがとうございました。In this case, saying すみません would be incorrect, since the level of gratitude when buying something is higher than the level of gratitude to someone holding the button on the elevator for you.
As a side note, even Japanese sometimes argue about when it is appropriate to use すみません or ありがとう. And there is perhaps dialectal gradation.
(see here for full data)
Green markers on the map indicate they use "sorry" word to tell gratitude in the local dialect. You can see them distributed in wide area, intermixed with other expressions.
Ultimately you'll notice how few Japanese dialects actually have the word literally translated "thank you" (ありがとう, which means "preciously", is no exception). Each color on the map stands for: